You can buy the oem open Crosman sights and put them on that gun, or buy a Crosman barrel that has them already. To be clear on that second option; ordering the barrel that normally has open sights does not guarantee it'll show up with said sights, so I'd also order the sights. The barrel is <$16US and the sights are prolly $1.15ea but not sure since I never bought them, plus $4 flat rate ship. You should also buy a new main seal, if you're interested in taking the gun apart... Some people that have a shrouded barrel want open sights so I suggest to them getting the oem rear right and mounting that normally, then since the shroud is fat you need a shorter front sight which you can either buy and cut up an oem unit or make one however you want. You'd attach it to the alum tube of the shroud which you can easily index which I spoze is a nice bonus. I mention that b/c I usually buy a shrouded barrel for guns like yours b/c #1 they're quieter, but also feel better cocking and look better imo. Same $ +~$3.50 for the shroud assy. Plus your choice of caliber if you wanted to change.
I hate open sights on break barrels since that's where I want to put my hand to cock it, so optionally you can mount it back a few inches so it's not in the way and that's easier with a shroud. The shroud itself is only $1.15 so no worries ruining it in your efforts or changing your mind.
The Crosman sights are plastic and rather cheap by any standards. They work but they can't take a hit, so an option is getting a metal one from a better gun. Your barrel block has no holes for mounting so you'd need to drill/tap or just epoxy it on, and it's so light I rekon a little dab of epoxy or krazy glue on ea corner would be good.
I've often shot break barrel guns w/o sights, like yours minus scope using the barrel block and muzzle end as my sights just like a scatter gun minus the little bead. For your close range it works very well imo, plus you're reducing your sight height which can help at such close range.
I don't have any issues using a scope for quick aquisition since I basically get close using the barrel and/or scope body as a guide, then quickly switch to the reticle. One problem with yours using a scope your sight height is even higher, too high imo. For example when I shoot at say 4-6' to get a gopher, the scope is so far off it's better to use the the side of the barrel instead as my sight.
Pretty much all those guns have barrel droop to some degree, but that's an advantage when it comes to scope sight height. You should also shim the scope which also reduces height, as will lower scope mounts if you can find them. I'm saying this b/c I'd push the limits of the scope setup b4 I'd go to open sights, but up to you.
I've yet to see a red dot that I preferred over a scope, and I can say the cheapie ones for $15 are not worth buying for any reason.
One last idea; a cheapie laser sight mounted on (under?) the barrel should work very well. I bought a rather bright green one that sits extemely low for $20 on ebay, which no doubt is much brighter than a generic red one.